The W.A. Shands Teaching Hospital of the University of Florida serves as the major referral center within a 300-mile-radius offering comprehensive, multimodal therapy for children with malignant disease, regardless of their ability to pay. Sixty-six of these pediatric oncology patients are totally medically indigent and the majority of the remainder can afford to pay only a fraction of their treatment costs. At the time of a malignancy in a child, the clinical findings are reviewed and management discussed at a weekly multidisciplinary Tumor Board conference by pediatric oncologists, radiation therapists, surgeons, pathologists, and other appropriate specialists to ensure that each patient receives optimal therapy. Access to new intensive multimodal therapeutic regimens and experimental compounds is facilitated by the collaboration of the Center with the Southwest Oncology Group. A variety of ancillary studies, both at the clinical and the preclinical levels are being performed in the Pediatric Oncology patients at the University of Florida in tandem with SWOG protocol investigations. The technique of thoracoscopy has been evaluated and perfected in the surgical laboratory to the point that it now provides major assistance in the diagnosis and management of a variety of pediatric malignancies. Application of the technique of cryosurgery to childhood cancer management is now entering the phase of clinical application, having been assessed initially in animal investigations. Polyamine measurement in blood, urine, bone marrow and cerebrospinal fluid are undergoing evaluation as a marker of disease activity. A Phase I-II clinical trial of vindesine in childhood leukemia has been performed in collaboration with the University of Kansas and a Phase II clinical trial of vindesine is being proposed to the Southwest Oncology Group. The relative effectiveness of various antibiotic regimens in the management of fever and neutropenia in children with malignancy is also undergoing assessment. Finally, protocols are being formulated by members of the U. of F. SWOG program for treatment of metastatic osteosarcoma and histiocytosis X in bone, and for evaluation of the significance of myelofibrosis in ALL.